My boss has been supportive of my love for open-source, but I've never really been able to make him understand what makes it commercially viable. I think I finally blundered across the right analogy, though.
Simon and Schuster could develop a proprietary written language for their authors to write fiction in. Then, they could try to persuade people to learn Simon-and-Schusterese in order to read their books. In fact, if they did a fantastic job of marketing, they might persuade people to buy the right to learn Simon-and-Schusterese, then buy the books. Meanwhile, their legal department would chase down anybody using Simon-and-Schusterese without proper payment and licensing. Random House, HarperCollins, etc. could do the same with their own proprietary corporate languages. It's vastly more practical, though, for everybody to write in - and sell in - a language that nobody owns, everyone can use, and everyone contributes to.
Of course, in the real world, shared human languages came before publishing companies. But if, somehow, things had happened the other way around, you can see how there would be some initial skepticism (What? Give away our language for free? When we could charge money for it?), but companies that started working with a shared language would eventually dominate, and society would be much richer and more literate for it.